A heater mechanism of the type to which the present invention relates, incorporates a thermoelectric converter for supplying electrical power for a typical solid, liquid or gas fueled heater for (a) sustaining the heater operation after a brief start-up period; (b) supplying power for providing fuel to the heater, for cooling the heater, removing waste heat from the converter and transporting the heat to a useful location remote from the heater, passenger compartment blower; and (c) recharging the start-up battery to insure adequate battery energy for subsequent start-up operations. The removal (or rejection) of heat from the thermoelectric converter cold side and the transport of the heat may be accomplished by either liquid or gaseous transport media (including heat pipes) and by pumping and/or blower devices. However, for highly compact self-powered heater systems either a liquid cooled system or a heat pipe cooled system would be required.
Prior thermoelectric converter designs employed a series arrangement of the components from the heat source to the heat sink. In these designs, the heat was directed in series from the combustion zone through the hot frame (or heat distribution member), thermoelectric stack elements, piston (or cold side compliance member), module bar or heat sink (or heat exchanger) and then to the coolant (gas or liquid). This series arrangement of components whether in a cylindrical or rectangular configuration, uses more volume than necessary and is therefore, unnecessarily large and bulky.
Thermoelectric stacks of prior devices have consisted of one of two basic approaches. In a first approach, a relatively large number of individual parts were assembled laboriously by hand stacking one part on top of another and ultimately the stacked parts were placed under spring pressure at final assembly. This approach was called a pressure contacted system, and because of the many loose parts, does not lend itself readily to automated assembly. In a second approach, several parts of the thermoelectric stack are bonded together at the hot side as individual couples. The couples are then installed into the converter as a matrix usually in a solid thermal insulation piece. The thermoelectric circuit is then completed by a second bonding step which attaches cold side electrical strips to the couples. Other loose parts must be added to this bonded component, that is, hot side dielectric material, cold side pistons, springs and heat sink(s), to complete the converter. The large number of parts and multiple operations do not lend themselves to mass production or automated assembly methods.
Furthermore, prior art, as known from patents U.S. Pat. No. 4,843,273 and 4,753,682 etc., has not addressed the problems of designing self-powered heaters for use in vehicle engine compartments where space and to some extent weight are at a premium; nor have they addressed the even more critical design considerations of reducing the parts count, or identifying cost effective fabrication and assembly methods in order to make the thermoelectric converter mass producible commercially.